WIFI appliations

What are WiFi antennas used for?

A Wi-Fi antenna is a crucial device when looking to enhance the Wi-Fi signal strength and range. It's of great use whenever a network or signal gets absorbed by nearby obstacles such as walls and metallic surfaces, affecting the connection between devices or the internet.

What are the disadvantages of WiFi antenna?

• Limited Range: Internal antennas are typically less effective at transmitting and receiving signals over long distances. ...

• Reduced Signal Strength: Internal antennas may have weaker signal strength, which can result in decreased signal penetration through walls and obstacles.

Introduction to Wi-Fi Wireless Antennas

Wi-Fi wireless networking sends radio transmissions at specific frequencies where listening devices can receive them. The radio transmitters and receivers are built into Wi-Fi-enabled equipment such as routers, laptops, and phones.

Antennas are key components of these radio communication systems. Antennas pick up incoming signals or radiate outgoing Wi-Fi signals. Some Wi-Fi antennas, particularly on routers, are mounted externally, while others are embedded inside the device's hardware enclosure.

Antenna Power Gain

The connection range of a Wi-Fi device depends on the antenna power gain. Gain is a numeric quantity measured in relative decibels (dB) representing the maximum effectiveness of an antenna compared to a standard reference antenna. Industry manufacturers use one of two standards when quoting gain measures for radio antennas:

• dBi: Decibels relative to an isotropic reference antenna.

• dBd: Decibels relative to a dipole reference antenna.

Most Wi-Fi antennas use dBi as the standard measure rather than dBd. For example, dipole reference antennas work at 2.14 dBi, which corresponds to 0 dBd. Higher values of gain indicate an antenna can work at higher levels of power, which usually results in a greater range.

Omnidirectional Wi-Fi Antennas

Some radio antennas work with signals sent out and received from all directions. These omnidirectional antennas are commonly used on Wi-Fi routers and mobile adapters, supporting connections from multiple directions.

Factory Wi-Fi gear often uses basic dipole antennas of the rubber duck design. This design is a helix shape sealed in a protective jacket of rubber or plastic that protects the antenna, like those used on walkie-talkie radios. These have a gain between 2 and 9 dBi.

Directional Wi-Fi Antennas

Because the power of an omnidirectional antenna is spread across 360 degrees, its gain measured in any one direction is lower than directional antennas that focus more energy in one direction. As a result, directional antennas are typically used to extend the range of a Wi-Fi network into hard-to-reach corners of buildings or in situations where 360-degree coverage isn't needed.

Cantenna is a brand name of Wi-Fi directional antennas. The Super Cantenna supports 2.4 GHz signaling with a gain of up to 12 dBi and a beamwidth of about 30 degrees, suitable for indoor or outdoor use. The term cantenna also refers to generic do-it-yourself antennas using a simple cylindrical design.

A Yagi (more properly called Yagi-Uda) antenna is another directional radio antenna that you can use for long-distance Wi-Fi networking. These antennas are extremely high gain, usually 12 dBi or higher, and extend the range of outdoor hotspots in specific directions or to reach an outbuilding. Do-it-yourselfers can make Yagi antennas, although the process requires more effort than making cantennas.